Brussels (Hybrid) or Remote within Spain | Occasional travel required I'm currently working with a leading international organisation operating in a highly secure, multinational environment, supporting critical systems and services used across multiple countries .They are looking for an experienced Senior. NET Web Developer to join a team building and maintaining enterprise-grade web applications that are secure, scalable and designed for long-term impac t.What you'll be do ing Designing, developing and maintaining modern web applications across the full software development lifecyc le. Building robust backend services using. NET and Entity Framework Co re. Developing modern frontend applications using Java Script and Svelte/Svelte K it. Creating and consuming REST APIs to integrate with enterprise systems and identity servic es. Contributing to architecture, application security, performance and scalability improvemen ts. Working within CI/CD environments and supporting cloud-ready application deploymen ts.What we're looking for Strong experience developing enterprise web applications using modern. NET technolog ies. Solid knowledge of:. NET (current LTS versi ons)Entity Framework Core REST API design and integra tion SQL Se rver Java Sc ript Svelte / Svelt e Kit Experience with secure software development practi ces. Familiarity with CI/CD pipelines, monitoring and application lifecycle managem ent. Experience working with Git and modern development tool ing. Strong English communication ski lls.Nice to have Experience deploying applications to cloud environm ents. Knowledge of identity and authentication sys tems. French language sk ills. Experience working in international, public sector, defence or highly regulated environm ents.Why join?Work on meaningful projects with real-world i mpact. Modern technology stack with both backend and frontend owne rship. International and collaborative enviro nment. Flexible working model: Brussels or remote within E urope. Long-term projects focused on quality, security and innov ation.